A completely automated public Turing test to tell computers and humans apart (“CAPTCHA”) is a type of challenge-response test that may be used to determine whether a device (e.g., a computer device) is being operated by a user (e.g., a human) or by the device (e.g., an automated process being performed by the computing device). A CAPTCHA image may require the user to correctly transcribe distorted characters (e.g., letters) included in the CAPTCHA image (e.g., a device may be unable to identify the distorted characters).